The present method of making color negatives, transparencies and prints, require the use of color compensating filters to control the attenuation principally of the red, green and blue parts of the light spectrum to insure color balance in pictures recorded on colored film and to compensate for the deficiencies in the spectrual quality of the light sources. The present methods used for the making of such negatives, transparencies or prints utilize a white light source and convert the same to light sources having different wave lengths which are used to simultaneously expose the various color emulsions on the film to match the quality of light for which the color film is balanced. Such light sources may be single or plural lights and employ a variety of filtering arrangements including compensating filters, light balancing and conversion filters and diffusion filters for proper exposure of the film.
In the making of color spearations for the printing of color pictures, it is necessary to make a plurality of sequential exposures of separate films with different light sources so that the proper amounts of printing ink may be applied to the resulting picture for proper reproduction and color balance. In the making of color separations, it is necessary for printing to make half tone negatives for the different printing inks and because of the inefficiency of printing inks, it is desirable to mask the transparency in the making of a separation, to bring the range of density of the transparency into one which is capable of printing on paper and to correct for hue error. Different colored light is used to expose each film for each separation and the present method employs a single light source with conversion filtering to insure proper exposure of the film for each color separation. At the present time, the filtering required the densities encountered and mechanics involved in making color separations requires the use of high powered large lights which generate vast amounts of unwanted heat. This results from the nature of the original source, the absorption of a large portion of the radiant energy spectrum through filtering, the use of half tone screens, and the density of the transparency itself. Further, since small transparencies are generally used and enlarging takes place, the problem of providing sufficient light for proper exposure of the film is compounded.